Other assets - Text Details (Detail) - EUR (€) € in Millions	Dec. 31, 2019	Dec. 31, 2018
Current assets [Member]
Other assets - Text Details (Detail) [Line Items]
Accrued income	€ 288	€ 276
Current prepaid expenses	188	193
Non-current assets [member]
Other assets - Text Details (Detail) [Line Items]
Non-current prepaid expenses	€ 47	€ 47

The amount recognised as a current asset for expenditures made prior to the period when the economic benefit will be realised.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 112
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2019-03-27

Name:	ifrs-full_CurrentPrepaidExpenses
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant